Submersible pumping system and method

ABSTRACT

A method of isolating a production fluid from a fluid-containing reservoir is provided. The method includes disposing a first pump within a horizontal section of a production well. The method also includes disposing a second pump within a vertical section of the production well. Further, the method includes pumping a reservoir fluid via the first pump towards the second pump. The method also includes capturing at least a portion of the reservoir fluid from the first pump in a fluid-retaining section located around the second pump. Furthermore, the method includes pumping the reservoir fluid captured in the fluid-retaining section to a fluid containment vessel via the second pump to provide an isolated production fluid.

BACKGROUND

The present technology relates generally to fluid pumps and, more specifically, to submersible fluid pumps of the type used in wells such as oil wells for handling multiphase fluids.

Generally, pumping systems are used in a wide variety of environments, including wellbore applications for pumping production fluids, such as water or petroleum. The pumping systems typically include, among other components, a submersible pump that provides for the pumping of high volumes of fluid, such as for use in oil wells which produce large quantities of water, or high volume water wells and a submersible motor for operating the electric submersible pump. A typical submersible pump utilizes numerous pump stages for pumping fluid to the surface from the well. Recovery of hydrocarbon resources has led to the development of advanced drilling and completion strategies for wells in gas and oil reserves. Many of these wells deviate from a straight path in order to enter production zones and follow geological formations that are often within a narrow band. Further, these directionally drilled wells for production of natural gas or shale oil often extend vertically down to reach the depth of the production formation and then extend horizontally along the formation. The flow of fluids produced in the horizontal section can be very non-uniform depending on the rates at which fluids including water, oil, and gas enter the flow. The fluids may flow in slugs or streams depending on the inclination of the wellbore. Furthermore, the proppants such as sand used in hydraulic fracturing procedures may remain in the wellbore after well completion and additional solids may be produced throughout the life of the well. This causes inferior production rates by the traditional pumping systems due to difficulty in maintaining required head pressure and handling multiphase fluids. The life of the pumps is also degraded by the solids.

There is therefore a desire for a system and method that allow increased production rates and life of the pumping systems used in deviated wellbores.

BRIEF DESCRIPTION

In accordance with an example of the technology, a method of isolating a production fluid from a fluid-containing reservoir is provided. The method includes disposing a first pump within a horizontal section of a production well. The method also includes disposing a second pump within a vertical section of the production well. Further, the method includes pumping a reservoir fluid via the first pump towards the second pump. The method also includes capturing at least a portion of the reservoir fluid from the first pump in a fluid-retaining section located around the second pump. Furthermore, the method includes pumping the reservoir fluid captured in the fluid-retaining section to a fluid containment vessel via the second pump to provide an isolated production fluid.

In accordance with an example of the technology, a pumping system for isolating a production fluid from a fluid-containing reservoir is provided. The pumping system includes a first pump configured to be deployed in a horizontal section of a production well for pumping a reservoir fluid. The pumping system also includes a second pump configured to be deployed in a vertical section of the production well. The pumping system further includes a second pump configured to be deployed in a vertical section of the production well. The first pump and the second pump are in fluid communication via a production tubing string.

In accordance with an example of the technology, a subterranean pumping system is provided. The subterranean pumping system includes a first pump configured to be deployed in a horizontal section of a production well for pumping a reservoir fluid. The subterranean pumping system also includes a second pump configured to be deployed in a vertical section of the production well. Further, the subterranean pumping system includes a fluid-retaining section disposed around the second pump for holding fluids that are pumped from the first pump. Further, the subterranean pumping system includes a control system configured for controlling flow of fluids pumped from the first pump, the second pump and maintaining pan optimal level of fluids in the fluid-retaining section.

DRAWINGS

These and other features, aspects, and advantages of the present technology will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

FIG. 1 is a schematic view of a pumping system for pumping a multiphase fluid in accordance with an embodiment of the present invention;

FIG. 2 is a schematic view of a pumping system for pumping a multiphase fluid in accordance with another embodiment of the present invention;

FIG. 3 is a schematic view of a pumping system for pumping a multiphase fluid in accordance with another embodiment of the present invention;

FIG. 4 is a schematic view of a pumping system for pumping a multiphase fluid in accordance with yet another embodiment of the present invention;

FIG. 5 of isolating a production fluid from a fluid-containing reservoir in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION

When introducing elements of various embodiments of the present technology, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Any examples of operating parameters are not exclusive of other parameters of the disclosed examples.

FIG. 1 is a schematic view of a pumping system 10 for pumping a multiphase fluid in accordance with an embodiment of the present invention. In the exemplary embodiment, the pumping system 10 includes a first pump 12 that is located in a horizontal section 14 of a production well 16 at an upstream side 18. The pumping system 10 also includes a second pump 22 located in a vertical section 24 of the production well 16 at a downstream side 26. Both the first pump 12 and the second pump 22 are in fluid communication via a first fluid conduit 20. The second pump 22 is in fluid connection with a wellhead 28 located aboveground via a second fluid conduit 23 located in the vertical section 24. The pumping system 10 may be operated in any location that permits the pumping system 10 to operate as described herein, e.g., aboveground to transfer a multiphase fluid from one storage location to another. Such multiphase fluids may contain high volumes of gas and solids 21 including various mixture of gases, water, sand, crude oil and the like. In the exemplary embodiment, the production well 16 is a deviated wellbore used for oil production, where a petroleum fluid includes a gaseous and liquid multiphase fluid. As used herein, the term “petroleum fluid” refers broadly to mineral hydrocarbons, such as crude oil, natural gas, and combinations of oil and gas.

Further, the pumping system 10 includes a fluid-retaining section 25 disposed around the second pump 22. The production well 16 is divided between two sections forming a first zone that encloses the first pump 12 and a second zone that encloses the second pump 22 by disposing a production packer 27. The second zone enclosing the second pump 22 forms the fluid-retaining section 25 configured to capture the reservoir fluid pumped from the first pump 12. The captured reservoir fluid in the fluid-retaining section 25 is pumped by the second pump 22 to the wellhead 28 above ground and further to a fluid containment vessel 30.

Furthermore, each of the first pump 12 and the second pump 22 are controlled by a first power supply unit 32 and a second power supply unit 34 respectively located above ground. It is to be noted that each of the first power supply unit 32 and the second power supply unit 34 includes an electrical supply unit, a hydraulic supply unit, and a pneumatic unit. Non-limiting examples of each of the first pump 12 and the second pump 22 includes a turbo pump, a progressive cavity pump, a reciprocating piston pump and a jet pump. The turbo pump may include a centrifugal pump or an axial pump and combinations thereof. Further, in one example each of the first pump 12 and the second pump 22 is a multistage pump. In one embodiment, the first pump 12 includes an electric submersible pump having one or more helico-axial configuration for pumping multiphase fluids having, high gas volume fractions. The second pump 22 includes an electric submersible pump having one or more pump stages in radial or mixed flow configuration for generating desired head pressure for lifting the fluids from the fluid-retaining section 25 to the wellhead 16 located aboveground. As shown, the pumping system 10 includes a first power delivery conduit 36 and a second power delivery conduit 38 that are disposed in the production well 16 for delivering power from the first power supply unit 32 and the second power supply unit 34 to the first pump 12 and the second pump 22 respectively.

FIG. 2 is a schematic view of a pumping system 11 for pumping a multiphase fluid in accordance with another embodiment of the present invention. As shown in this embodiment, the first zone in the horizontal section 14 includes the first pump 12 along with one or more pumps 13, 15. The first pump 12 and the one or more pumps 13, 15 may be jet pumps and configured to pump reservoir fluids from the first zone in the horizontal section 14 to the fluid-retaining section 25. The second pump 22 located in the second zone within the fluid-retaining section 25 may be an electric submersible pump configured to pump the reservoir fluid contained in the fluid retaining section 25 to the wellhead 28 above ground.

FIG. 3 is a schematic view of a pumping system 40 for pumping a multiphase fluid in accordance with another embodiment of the present invention. In this embodiment, the pumping system 40 includes a first pump 12 that is an electric submersible pump connected with a first variable frequency drive 42 and the first power supply unit 32 via the first power conduit 36. Similarly, the pumping system 40 includes a second pump 22 that is also an electric submersible pump connected with a second variable frequency drive 44 and the second power supply unit 34 via the second power conduit 38.

Further, the pumping system 40 may be operated by a control system 46 located aboveground and configured for controlling flow rate of fluids pumped from the first pump 12 and the second pump 22. In one embodiment, the pumping system 40 includes one or more control systems located above or below ground and configured to control the operating speed of the first pump 12 and the second pump 22. Alternatively, the pumping system 40 may be operated to pump any gaseous and liquid multiphase fluid that permits pumping system 40 to operate as described herein. The control system 46 may also be configured to maintain an optimal level of fluids in the fluid retaining section 25.

In one embodiment, as shown in FIG. 4, a pumping system 50 includes a fluid-retaining section 52 that has a cylindrical shroud section 54 arranged around the second pump 22 forming a basin for holding reservoir fluids that are pumped from the first pump 12. In this embodiment, an inlet 56 of the second pump 22 is located within the cylindrical shroud section 54 for allowing intake of reservoir fluids that are further pumped to the wellhead 28 above ground and to the fluid containment vessel 30. The second pump 22 is controlled by the second power supply unit 34 such that a liquid level 58 is maintained above the inlet 56 of the second pump 22. This ensures there is sufficient flow of reservoir fluids into the second pump 22 for further pumping to the wellhead 28.

FIG. 5 is a flow chart of a method 100 of isolating a production fluid from a fluid-containing reservoir in accordance with an embodiment of the present invention. At step 102, the method includes disposing a first pump within a horizontal section of a production well. At step 104, the method includes disposing a second pump within a vertical section of the production well. Further, at step 106, the method includes pumping a reservoir fluid via the first pump towards the second pump. The reservoir fluids include a flow of multiphase fluids and solid matter such as mixture of gases, water, sand, crude oil, and the like. The method also includes powering the first pump and the second pump using a first power supply unit and a second power supply unit via a first power delivery conduit and a second power delivery conduit respectively that are disposed in the production well. Each of the first power supply unit and the second power supply unit includes an electrical supply unit, a hydraulic supply unit, and a pneumatic unit. Moreover, each of the first pump and the second pump is a multistage pump including a turbo pump, a progressive cavity pump, a reciprocating piston pump and a jet pump. The turbo pump used as the first pump or the second pump may include centrifugal pump or an axial pump and combinations thereof. In one embodiment, the first pump includes an electric submersible pump having at least one or more helico-axial configuration for pumping multiphase fluids having high gas volume fractions. The second pump includes an electric submersible pump having at least one or more pump stages in radial or mixed flow configuration for generating desired head pressure for lifting the fluids from the fluid retaining section to the wellhead located aboveground. In one embodiment, the method further includes isolating a first zone having the first pump from a second zone having the second pump in the production well by disposing a production packer, where the second zone is the fluid-retaining section. In another embodiment, the fluid-retaining section comprises a cylindrical shroud section arranged around the second pump comprising a basin for holding fluids that are pumped from the first pump. At step 108, the method includes capturing at least a portion of the reservoir fluid from the first pump in the fluid-retaining section located around the second pump. Finally at step 110, the method includes pumping the reservoir fluid captured in the fluid-retaining section to a fluid containment vessel via the second pump to provide an isolated production fluid. The method also includes controlling a flow of fluids pumped from the first pump, the second pump and maintaining an optimal level of reservoir fluids in the fluid retaining section by one or more control systems. In one embodiment, a reservoir fluid level is always maintained above an inlet of the second pump for ensuring sufficient flow of reservoir fluids into the second pump 22 for further pumping to the wellhead 28. The one or more control systems are located above or below ground and configured to control the operating speed of the first pump and the second pump.

Advantageously, the present invention is directed towards improving operability and durability of the pumping system used in directionally drilled wells. The present pumping system and method allows efficient pumping of multiphase fluids including solids, liquids and gases in production of unconventional oil and gas wells.

Furthermore, the skilled artisan will recognize the interchangeability of various features from different examples. Similarly, the various methods and features described, as well as other known equivalents for each such methods and feature, can be mixed and matched by one of ordinary skill in this art to construct additional systems and techniques in accordance with principles of this disclosure. Of course, it is to be understood that not necessarily all such objects or advantages described above may be achieved in accordance with any particular example. Thus, for example, those skilled in the art will recognize that the systems and techniques described herein may be embodied or carried out in a manner that achieves or improves one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.

While only certain features of the technology have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the claimed inventions. 

1. A method of isolating a production fluid from a fluid-containing reservoir, the method comprising: (a) disposing a first pump within a horizontal section of a production well; (b) disposing a second pump within a vertical section of the production well; (c) pumping a reservoir fluid via the first pump towards the second pump; (d) capturing at least a portion of the reservoir fluid from the first pump in a fluid-retaining section located around the second pump; and (e) pumping the reservoir fluid captured in the fluid-retaining section to a fluid containment vessel via the second pump to provide an isolated production fluid.
 2. The method of claim 1, further comprising controlling a flow of fluids pumped from the first pump, the second pump and maintaining an optimal level of fluids in the fluid retaining section by one or more control systems.
 3. The method of claim 1, wherein the one or more control systems are located above or below ground and configured to control the operating speed of the first pump and the second pump.
 4. The method of claim 1, wherein the reservoir fluids comprises a flow of multiphase fluids and solid matter.
 5. The method of claim 4, wherein the multiphase fluids comprises a mixture of gases, water, sand, crude oil, and the like.
 6. The method of claim 1, wherein each of the first pump and the second pump are controlled by a first power supply unit and a second power supply unit respectively.
 7. The method of claim 6, further comprising powering the first pump and the second pump using the first power supply unit and the second power supply unit via a first power delivery conduit and a second power delivery conduit respectively that are disposed in the production well.
 8. The method of claim 7, wherein each of the first power supply unit and the second power supply unit comprises an electrical supply unit, a hydraulic supply unit, and a pneumatic unit.
 9. The method of claim 1, wherein each of the first pump and the second pump is a multistage pump comprising a turbo pump, a progressive cavity pump, a reciprocating piston pump and a jet pump.
 10. The method of claim 9, wherein the turbo pump comprises a centrifugal pump or an axial pump and combinations thereof.
 11. The method of claim wherein the first pump comprises an electric submersible pump having at least one or more helico-axial configuration for pumping multiphase fluids having high gas volume fractions.
 12. The method of claim 1, wherein the second pump comprises an electric submersible pump having at least one or more pump stages in radial or mixed flow configuration for generating desired head pressure for lifting the fluids from the fluid retaining section to the wellhead located aboveground.
 13. The method of claim 1, further comprising isolating a first zone having the first pump from a second zone having the second pump in the production well by disposing a production packer.
 14. The method of claim 13, wherein the second zone is the fluid-retaining section.
 15. The method of claim 13, wherein the first zone in the horizontal section comprises one or more pumps along with the first pump.
 16. The method of claim 1, wherein the fluid-retaining section comprises a cylindrical shroud section arranged around the second pump comprising a basin for holding fluids that are pumped from the first pump.
 17. A pumping system for isolating a production fluid from a fluid-containing reservoir comprising: a first pump configured to be deployed in a horizontal section of a production well for pumping a reservoir fluid; a second pump configured to be deployed in a vertical section of the production well; and a fluid-retaining section disposed around the second pump, wherein the first pump and the second pump are in fluid communication via a first fluid conduit.
 18. The system of claim 17, wherein each of the first pump and the second pump are controlled by a first power supply unit and a second power supply unit respectively.
 19. The system of claim 17, further comprising a first power delivery conduit and a second power delivery conduit that are disposed in the production well configured for powering the first pump and the second pump respectively using the first power supply unit and the second power supply.
 20. The system of claim 19, wherein each of the first power supply unit and the second power supply unit comprises an electrical supply unit, a hydraulic supply unit, and a pneumatic unit.
 21. The system of claim 17, wherein each of the first pump and the second pump is a multistage pump comprises a turbo pump, a progressive cavity pump, a reciprocating piston pump and a jet pump.
 22. The system of claim 21, wherein the turbo pump comprises a centrifugal pump or an axial pump and combinations thereof.
 23. The system of claim 17, wherein the first pump comprises an electric submersible pump configured for pumping multiphase fluids having high gas volume fractions and comprising at least one or more helico-axial configuration.
 24. The system of claim 17, wherein the second pump comprises an electric submersible pump having at least one or more pump stages in radial or mixed flow configuration configured to generate desired head pressure for lifting the fluids from the fluid retaining section to the wellhead located aboveground.
 25. The system of claim 17, further comprises a production packer disposed in the production well configured to separate a first zone and a second zone, wherein the second zone is the fluid retaining section.
 26. The system of claim 17, wherein the fluid-retaining section comprises a cylindrical shroud section arranged around the second pump comprising a basin for holding fluids that are pumped from the first pump.
 27. A subterranean pumping system comprising: a first pump configured to be deployed in a horizontal section of a production well for pumping a reservoir fluid; a second pump configured to be deployed in a vertical section of the production well; a fluid-retaining section disposed around the second pump for holding fluids that are pumped from the first pump; and a control system configured for controlling flow of fluids pumped from the first pump, the second pump and maintaining an optimal level of fluids in the fluid-retaining section.
 28. The system of claim 27, further comprises a production packer disposed in the production well configured to separate a first zone and a second zone, wherein the second zone is the fluid retaining section.
 29. The system of claim 27, wherein the fluid-retaining section comprises a cylindrical shroud section arranged around the second pump comprising a basin for holding fluids that are pumped from the first pump. 